The H1 60″ Roller with 36″ Extension Plates extends the contact point of the rack passed the rear door. Eliminating damages that may occur when loading and unloading Ladders, pipes and other material or equipment. Extension Plates and Roller are made from aluminum. The roller is slightly lower than the cross bars on the rack to not interfere the placement of your equipment. This roller system will fit onto the Vantech H1 mounts, connected via the H1 eye hooks. Fits Nissan NV Cargo Van Low Roof and High Roof.